Mine used to sleep through the night, when they were very little. From what I have seen and heard, my ducks (runners) are nappers. They sleep a few hours, bills tucked under wings, perhaps cooing a little, then they are up looking around.
I smiled to see your question today, because last night, for the first time in a long time, if ever, my duck Sechs woke up around 2:30 a.m. feeling very chatty. Not yelling, not alarmed, just chatting. Around 3 a.m. I decided to try turning out their night light (in the past when I have tried this, mayhem ensued). Click, off the light. I waited. After a bit, her chatter subsided and then stopped. No mayhem. Good night, duck sweeties.
Tonight I think we will try going without the light all night.